Here you can find an overview of the different ways to comment and sort existing posts. Attention: we've used the "diabook" theme. If you're using another theme, some of the icons may be different.
The different icons
This symbol is used to indicate that you like the post. Click it twice to undo your choice.
This symbol is used to indicate that you dislike the post. Click it twice to undo your choice.
This symbol is used to share a post. A copy of this post will automatically appear in your status editor and add a link to the original post.
This symbol is used to mark a post. Marked posts will appear on your network page at the "starred" tab (from "star"). Click it twice to undo your choice.
This symbol is used to tag a post with a self-chosen keyword. When you click at the word, you'll get a list of all posts with this tag. Attention: you can't delete the tag once you've set one.
This symbol is used to categorize posts. Choose an existing folder or create a new one. You'll find the created folder on your network page under the "saved folders" tab.
This symbol is used to delete your own post or to remove a post of another person from your stream.
This symbol is used to choose more than one post to delete in a single step. After selecting all posts, go to the end of the page and click "Delete Selected Items".
Symbols of other themes
Darkbubble 
Darkzero 
(incl. more "zero"-themes, slackr, comix, easterbunny, facepark)
Dispy 
(incl. smoothly, testbubble)
Frost Mobile 